2.8 flywheel question

[coheed]

So I've recently acquired another 86 with the 2.8 in it. This one however, has an AX5 that I believe to be the source of the horrible growling noise when driving down the road. I have a presumably good 904 trans in my old truck that I'm thinking of swapping in.

 

My question is, is the flywheel/flex plate balanced to a matched crankshaft, or can I swap the flex plate over and not have any vibration issues on the other motor?

[Eagle]

The version of the 2.8L that Jeep used was externally balanced. This means there is a counterweight on the flywheel / flexplate. If you have a Jeep 2.8L with the 904, everything should swap over with no problems.

[coheed]

7 hours ago, Eagle said:

The version of the 2.8L that Jeep used was externally balanced. This means there is a counterweight on the flywheel / flexplate. If you have a Jeep 2.8L with the 904, everything should swap over with no problems.

So they are not a matched pair? The balancing is not matched to the crank?

[Eagle]

55 minutes ago, coheed said:

So they are not a matched pair? The balancing is not matched to the crank?

 

Not the way you mean. All the cranks are the same, and all the flywheels are the same. As long as they are for the same engine (by family, not by individual serial number) any flywheel works with any crankshaft. But later GM 2.8L and 3.4L engines were internally balanced, so you can't use an AMC flywheel on one of those GM engines, and you can't stuff a later GM 2.8L crank into an AMC engine unless you also switch to a neutral-balanced flywheel.

 

No, there was no engine blueprinting room where each individual crankshaft was mated and balanced to a specific flywheel.